Tim Cook's departure from Apple marks the end of an era that saw the iPhone maker become the world's most valuable company—and one of its most scrutinized on environmental grounds.

Cook, who succeeded Steve Jobs in 2011, announced he will step down as CEO, handing control to John Ternus, Apple's senior vice president of hardware engineering, according to reports from TechCrunch and other outlets. The transition comes as Apple reaches a staggering $4 trillion valuation, a milestone that underscores Cook's business acumen but also raises urgent questions about the company's ability to meet its ambitious climate targets.

A Business Triumph With Environmental Asterisks

Under Cook's leadership, Apple expanded far beyond the iPhone. The company launched the Apple Watch, AirPods, and a services division that now generates over $80 billion annually. Apple's market capitalization grew more than tenfold during his tenure, cementing its position as a technology and cultural force.

But Cook's legacy is complicated by the environmental footprint of that growth. While Apple has made headline-grabbing commitments—including a pledge to become carbon neutral across its entire supply chain by 2030—the company's actual emissions tell a more sobering story.

Apple's total carbon footprint peaked at over 27 million metric tons of CO2 equivalent in recent years, driven largely by manufacturing and the energy-intensive production of devices like iPhones and MacBooks. The company has made genuine progress in some areas: its corporate operations run on 100% renewable energy, and it has pushed suppliers to follow suit. Apple claims that over 250 of its suppliers have committed to using clean energy for Apple production.

Yet critics point out that these supplier commitments often cover only a fraction of total manufacturing emissions, and Apple's device replacement cycles—driven by planned obsolescence and marketing—encourage consumption patterns fundamentally at odds with sustainability.

The Repair and Longevity Question

One of the most contentious environmental issues during Cook's tenure has been Apple's approach to device repairability. For years, the company resisted right-to-repair legislation and designed products that were difficult or impossible for consumers to fix themselves.

Apple eventually shifted course, launching a self-service repair program in 2022 and supporting some right-to-repair bills. But advocates argue the moves came too late and remain too limited. Devices that could last a decade often end up in landfills after three to five years, contributing to the global e-waste crisis that now exceeds 50 million metric tons annually.

"Apple has the engineering talent and resources to build phones that last 10 years," said Kyle Wiens, CEO of iFixit, in a recent interview. "The question has always been whether they have the will."

What Ternus Inherits

John Ternus takes over a company at a crossroads. He inherits Cook's carbon neutrality pledge with just six years remaining to achieve it—a timeline many experts consider unrealistic given the scale of Apple's supply chain and the continued growth in device sales.

Ternus, who has led hardware engineering since 2021 and played key roles in developing the M-series chips and recent iPhone models, has not publicly outlined his environmental priorities. His background suggests a focus on technical innovation, but whether that innovation will prioritize sustainability remains to be seen.

The transition also comes amid growing regulatory pressure. The European Union's Digital Product Passport requirements, set to take effect in the coming years, will force Apple to provide detailed information about the environmental impact and repairability of every device sold in the bloc. California and other U.S. states are advancing similar legislation.

The Climate Stakes

Apple's environmental impact extends beyond its own emissions. As one of the world's most influential companies, its design choices ripple across the entire consumer electronics industry. When Apple eliminated the charging brick from iPhone boxes, competitors followed. If Apple were to truly prioritize device longevity and repairability, the industry would likely shift in that direction too.

The company's $4 trillion valuation—a figure Cook will be remembered for—represents enormous capital that could be deployed toward genuine climate solutions. Apple's cash reserves alone exceed the GDP of most countries. How Ternus chooses to allocate those resources will determine whether Cook's environmental promises were genuine commitments or merely effective marketing.

Recent data suggests the window for corporate climate action is narrowing. Global temperatures are on track to exceed 1.5°C of warming within the next decade, according to the latest IPCC assessments. Tech manufacturing, which accounts for roughly 2-3% of global emissions, must decarbonize rapidly to prevent the worst climate outcomes.

A Legacy Still Being Written

Cook's defenders will point to tangible progress: renewable energy adoption, recycling programs like Daisy (the iPhone-disassembling robot), and investments in green bonds. These are real achievements that have moved the industry forward.

But Cook's critics will note the gap between Apple's soaring rhetoric and its material reality—a company that profits from selling hundreds of millions of new devices each year while promising sustainability.

As Ternus assumes control, he faces a choice that will define his own legacy: continue the incremental approach Cook pioneered, or fundamentally rethink Apple's business model to align with the climate crisis we're actually living through.

The next 15 years will reveal which path he chooses—and whether a $4 trillion company can truly become a climate solution rather than part of the problem.